How to assert the content of a service message exception in a Grails unit test - unit-testing

Question

I am using Grails 4.0.3 and want to assert that an exception is thrown in a given situation. Below, my PidService.
def validatePidIssuingConclusionDocument(JSONObject pidIssuingConclusionDocument){
String message = "Document issuing number is mandatory"
if(!pidIssuingConclusionDocument.has("docIssuingNumber")){throw new Exception(message)}
}
Below, my test case:
void "wrong document"() throws Exception {
JSONObject documentWithoutIssuingNumber = new JSONObject()
documentWithoutIssuingNumber.accumulate("docIssuingNumber","123")
pidService.buildPidIssuingOrder(documentWithoutIssuingNumber)
// How can I assert that the exception is thrown and verify it message.
}
I tried to use try/catch in the test case without success. Could anyone help me? I need to assert that the exception is thrown and the message is Document issuing number is mandatory in the given case.

Answer 1

I need to assert that the exception is thrown and the message is
Document issuing number is mandatory in the given case.
I can't provide an executable example around the code you provided because some things are missing (like buildPidIssuingOrder). See the project at https://github.com/jeffbrown/dnunesexception which contains an example that shows a way to deal with the exception in a test though.
grails-app/services/dnunesexception/PidService.groovy
package dnunesexception
import org.grails.web.json.JSONObject
class PidService {
def buildPidIssuingOrder(JSONObject pidIssuingConclusionDocument) {
throw new Exception('Document issuing number is mandatory')
}
}
src/test/groovy/dnunesexception/PidServiceSpec.groovy
package dnunesexception
import grails.testing.services.ServiceUnitTest
import spock.lang.Specification
import org.grails.web.json.JSONObject
class PidServiceSpec extends Specification implements ServiceUnitTest<PidService>{
void "test something"() {
when:
JSONObject documentWithoutIssuingNumber = new JSONObject()
documentWithoutIssuingNumber.accumulate("docIssuingNumber","123")
service.buildPidIssuingOrder(documentWithoutIssuingNumber)
then:
def e = thrown(Exception)
and:
e.message == 'Document issuing number is mandatory'
}
}